Stereoscopic x-ray system.



H. C. SNOOK & E. W. KELLY.

STEREOSCOPlC X-RAY SYSTEM.

APPLICATION FILED DEC. '4. 1914.

1,163,959. I Patented Decf14, 1915.

2 SHEETS-SHEET I.

I I A'ITQRNEY INVENTORS H. 0.. SNOOK & E. w. KELLY.

STEREOSCOPIC X-RAY SYSTEM. I

APPLICATION FILED DEC. 4, 1914 1,163,959. Patent ed De.14,1915.

2- SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

HOMER CLYDE 'SNOOK, OF CYNXVYD, AND EDWIN W. KELLY, OF PHILADELPHIA,

' PENNSYLVANIA.

STEREO SCOPIC X-RAY SYSTEM.

Patented Dec. 14, 1915.

Original application filed August 15, 1912, Serial No. 715,161. Divided and this application filed December To all whom it may concern: e,

Be it known that we, HOMER CLYDE SNOOK and EDWIN W. KELLY, citizens of the United States, of Cynwyd and Philadelphia, State of Pennsylvania, have invented new and useful Improvements in Stereoscopic X-Ray 'Systems, of which the following is a specification.

Our invention relates to a system of and apparatus for causing the production of X-rays from a plurality of anti-cathodes disposed either within one X-ray tube, or in separate X-ray tubes.

Our invention resides in a system of the character above referred to adapted for stereoscopic X-ray purposes, whereby an observer may see, by aid of X-rays, objects appearing in images in sterescopic relation,

that is, whereby an observer may see an obinvolving the use of a plurality of X-ray tubes, or a tube having a plurality of anticathodes, or a plurality of other similar translating devices, fm' whatever use intended; and in the case of the use of a plurality of X-ray tubes for the destruction of germs, larvae, or the like in or upon tobacco or other substance.

Our invention resides in the system and I apparatus hereinafter described and claimed.

For an illustration of some of the forms our invention may take, reference is to be had to the accompanying drawings, in which:

Figure 1 is an illustration, partly diagrammatic, of an application of our system and apparatus for stereoscopically viewing objects by the aid of X-rays. Fig. 2 is a graphic representation of a mode of use of the current waves. Fig. 3 is an illustration of an. X-ray tube having two anodes, one of them combined with a cathode. Fig. 4 is a Serial N 0. 875,409.

2 and 3, the former communicating with contact 4 and the latter through the adjustable resistance 5 with the contact 6, the contacts 4 and 6 being those of an electric switch 7 communicating with the service or supply conductors 8 and 9. At suitable points in the winding A taps are taken out to the slip rings 10 and 11, insulated from each other and communicating respectively with brushes 12 and 13, communicating with the reversing switch 14. From one terminal of the reversing switch 14 connection is made with the primary P, adjustable, if desired, as to the number of its turns, of a step-up transformer T whose secondary winding is S. The other terminal of the primary P is connected with the brush 15 bearing upon the circumferentially continuous slip ring 16 with which are electrically connected the commutator segments 17 and 18, these segments having relatively short circumferential extent. In the path of travel of the contact 17 is disposed the brush 19 adapted to engage said contact 17, the brush 19 communicating with the o-therterminal of the reversing switch 14 through the adjustable resistance 20. The brush 21 is adapted to engage the contact 18 as it passes said brush, and the brush 21 is connected with the same terminal of the reversing switch 14 through the adjustable resistance 22. The commutator comprising the ring 16, contacts 17 and 18, is secured upon the armature shaft 23 and rotates in fixed relation with respect to the armature.

One terminal of the secondary S connects with the brush 24 bearing upon the hub 25 of the rotating conductor 26, the hub 25 being insulated from the shaft 27, as indicated in Fig. 5, the shaft 27 being an extension of the armature shaft 23, or being a shaft rotating in synchronism or definite relation With the armature shaft 23. The outer end of the conductor 26, in its rotation, comes close and to the other terminal of the secondary S.

A fluorescent screen 34 is disposed in front of the anodes 32 and 33, the object 35, to be viewed, intervening between these targets or anodes and the screen 34. A rotating shutter 36 is disposed in front of the fluorescent screen 34 and is driven in fixed relation with the shaft 23 by the flexible shaft 37, or any other suitable means. The shutter 36, as seen in Fig. 4, has an arc shaped aperture 38, of width suitable to accommodate suitable vision by a human eye and of an angular extent substantially equal to the angular extent of the arcs 28 and 29 and the contacts 17 and 18. The positionof the eyes of the observer are indicated in Fig. 1, 39 representing the left eye and 40 representing the right eye.

Theoperation is as follows: Upon closure 01 the switch 7 the motor-generator G starts and is brought up to suitable speed by cutting out more or less of the resistance 5.

- The minimum speed is that which will produce a succession of images on the screen 34 such that the persistence of vision will not cause the. alternate images, as viewed through the shutter 36, to be separate and distinct images, or such that the impression made by one image does not disappear before the appearance of the, other image. With the motor-generator running at the desired speed there is impressed upon the slip rings 10 and 11 and brushes 12 and 13 an alternating potential. The circuit through the primary P is closed alternately through contact 17, brush 19 and contact 18 and brush 21, current being delivered through the primary P not during an entire potential or electro-motive-force wave, but only during a portion thereof, as indicated in Fig. 2, where the curved dotted line 41 represents a positive Wave and the dotted line 42 a negative wave. The contact 17 for example, allows current to flow through the primary P only during the time represented by the distance 43, and area 44 within the solid lines representing the amount and duration of the current energy passed through the primary P. After a. further half revolution of the shaft 23 the contact 18 comes into engagement with brush 21 and there flows through the primary P, but in opposite direction, energy represented by the area 45 taken from the negative half wave 42.

Assuming the parts momentarily in the position indicated in Fig. 1, energy is flowing through the primary P from contact 18 and brush 21 and from the secondary S to the anode 32 of tube IQ to the cathode 30,

on the screen 34 which is seen by the left eye 39 through aperture 38. At a half revolution later of the shaft 23 the primary P will be energized through contact 17 and brush 19 and the tube X will have its anode 33 brought into circuit through arc 29 and the conductor 26 which will then be in the dotted position, energy flowing between cathode 31 to anode 33 to the other terminal of the secondary S. X-rays will now be produced by the tube X and, the shutter 36 having made a half revolution also, the aperture 38 will be in front of the right eye 40 which will see the image on screen 34 produced by tube X These images are produced alternately and at such high speed that they are viewed separately by the left and right eyes but, due to the ersistence of vision, the effect upon the observer is the same as if he were viewing the object 35 continuously with both eyes, thus seeing all parts,'as it were, in their true relations with respect to each other, and just as any object visible under ordinary light is seen by both eyes.

Instead .of using two separate tubes X and X as indicated in Fig. 1, a single tube X' such as shown in Fig. 3 may be eniployed. Here the anode 32 and cathode 31 are combined and are connected to one ter ininal of the secondary S; and the other cathode-30 connected with the are 28 and the other anode 33 connected with the'arc 29. The principle is the same, 'but here all the anodes and cathodes are disposed within one tube within the same vacuum. With whatever care the tubes X, X or X are made, the dielectric cohesion between one anode and cathode will be'difierent from the dielectric cohesion between the other anode and its cathode, whether within the same or separate tubes, so that different potentials goo will have to be impressed upon the difi'ertator having the contacts 17 and 18 and the adjustable resistances 20 and 22. The tube X is supplied with energy derived through the resistance 22 and the tube X is supplied with energy derived through resist In Fig. 6 there is shown a system similar to that shown in Fig. 1, in that a two pole generator is employed. The generator, primary of the transformer and commutator,

etc, are omitted from Fig. 6, beiifg understood to be the same as or equivalent to those shown in Fig. 1. However the secondary S is shown and its one terminal is permanently connected to two points or contacts 74 74 disposed opposite each other and connected to each other. The other terminal of the secondary S connects with the anode 32 of tube X and with cathode 31 of tube X The cathode 30 of tube X connects with point or contact 75, while the anode 33 of tube X connects with point or contact 7 6 diametrically opposite to point or contact 75,

the. contacts 75 and 76 being disposed at right angles to the contacts 74 7 4. The disk 77 of insulating material carries the aluminum or other conducting arc 78 of substantially 180 extent. This is rotated by shaft 27 in synchronism with shaft 23 so that X-rays are tubes X and X In Fig. .7 an arrangement is shown where no rectification occurs but where a four pole generator is assumed. .Here the disk carries two aluminum or conducting arcs 79 and 80,

diametrically opposed and each of substantially 90 extent. By this arrangement the tubes X and X are excited alternately, but each is excited twice for each revolution at the armature of the generator.

In all cases where the apparatus is to be used for stereoscopy the targets or anodes. whether in the same or separate tubes, are placed substantially two and one half inches apart, the distance between the human eyes.

By the arrangement shown in Fig. 1 there is one mechanical cycle for one" electrical cycle. The same is true of Fig. 6. In Fig. 7 there are two electrical cycles for one mechanical cycle.

It is to be understood that our apparatus is not limited to stereoscopy, but may be used for any purpose where X-rays are to be produced alternately from different targets or anodes whether in. the same or separate tubes. Thus our apparatus may be used for the X-ray treatment of tobacco or other materials or substances, in which case how-.

ever separate tubes are preferable for the produced alternately by the reason that when excited alternately the tube not being excited can radiate heat generated in it before its next excitation, and liberate so much of such heat as will allow its continuous use in the system without at taining a dangerous over temperature.

It is to be understood that our invention is not limited to the use of such portion of a current wave as indicated in Fig. 2, for it is within our invention to use a greater or smaller fraction of a current wave or im pulse. And it is to be understood that our invention is not limited to the use of a motor-generator as described, for we may use any other means for producing the current supplied to the transformer, such as an alternating current generator driven by a separate or alternating current motor, or driven by* means of other than an electric motor. I v

A synchronous alternating current motor may be used in place of machine G, in which case the conductors attached to brushes 12 and 13 connect with the source of alternating current, but the commutator in the primary circuit of the transformer and the members 26, 37 and 68 are coupled to or driven in definite relation with respect to the rotating member of the synchronous motor. 7

The reversing switches 14 serve to reverse the direction of energy flow between anodes and cathodes, should the direction of flow-be wrong for any reason.

This application is a division from our prior application Serial Number 715,161, filed August 15, 1912, upon which Patent No. 1,123,942 issued on-January 5, 1915.

' What we claimis;

1. The combination with a plurality of X-ray producers, of a source of high tension alternating current, a connection from one terminal of said source to an anode of one of said producers and to a cathode of another .of said producers, switching mechanism directing energy of positive waves through one of said producers and energy of negative waves through another of said producers, a source of low tension current from which said alternating current is derived, and means in the circuit of said low tension source for controlling energy delivered to one of said X-ray producers independently of the energy delivered to another other terminal of said source alternately to I the cathode of said one of said X-ray producers and to theanode of said other of said X-ray producers, a source of low tension current from which said high tension current is derived, and means in the circuit of said low tension source controlling the energy delivered to one of said X-ray producers independently of the energy delivered to another of said X-ray producers. 3. The combination with a plurality of X- ray producers, of a step up transformer, a connection from one terminal of the secondary of said transformer to an anode of one and a cathode of another of said X-ray producers, a synchronous switch connecting the other terminal of said transformer secondary alternately to the cathode of said one and the anode of said other of said X- 'ray producers, and means in the primary circuit of said transformer controlling the energy delivered to one of said X-ray pro-' delivering positive and negative currents to said primary circuit through different branches, and current adjusting means in one of said branches. 7

5. The combination with a source of alternating current, of a transformer primary circuit having branches, synchronous commutating means delivering positive current waves through one of said branches and negative current waves through another of said branches, a plurality of X-ray producers, a connection from one terminal of the transformer secondary to an anode of one and a cathode of another of said X-ray producers, and a synchronous switch connecting the other terminal of said trans: former secondary alternately with the cathode of said one and the anode of said other of said X-ray producers.

6. The combination with a plurality of vacuum paths, of a source of positive and negative current waves, a connection' from one terminal of said sourceto an anode of one and a cathode of another of saidvacuum paths, a switch alternately connecting the other terminal of said source with the oathode of said one and the anode of said other of said vacuum paths, a circuit from which 531d positive and negative current waves are derived, and means in said circuit controlling the energy delivered through one of said vacuum paths independently of the energy delivered through another of said vacuum paths".

7. The combination with a plurality of vacuum paths, of a transformer, a connection from one terminal of the transformer secondary to an anode of one and a cathode of another of said vacuum paths, a synchronous switch alternately connecting the other terminal of said transformer secondary to the cathode of said one-and the anode of said other of said vacuum paths, synchronous switching means in the primary circuit of said transformer delivering positive and negative currents through different branches, and means for adjusting the relative current strengths in said branches.

8. The combination with a consumption circuit having a plurality of branches, of a transformer, a connection from one terminal of the transformer secondary to a common terminal of said branches, a synchronous switch alternately connecting the other terminals of said branches to the other terminal of said trans former secondary, a source of alternating current, synchronous switching means delivering the positive waves through one and the negative waves through another branch of the primary circuit of said transformer, and means for adjusting the relative current strengths in said primary branches;

9. The combination with a plurality of X-ray producers, of a source of high tension alternating current, a connection from one terminal of said source to an anode of one of said producers and to a cathode of another of said producers, switching mechanism directing energy of positive Waves through one of said producers and energy of negative waves through another of said producers, a source of low tension current from which said alternating current is derived, means in the circuit of said low tension source for controlling energy delivered to one of said X-ray producers independently of the energy delivered to another of said X-ray producers, afiuorescent screen, and a shutter between which and said X-ray producers said screen intervenes operating in synchronism with said alternating current.

10. The combination with a plurality of X-ray producers, of a source of high tension positive and negative current waves, a connection from one terminal of said source to an anode of one of said X-ray producers and p to a cathode of another of said X-ray producers, switching mechanism connecting the other terminal of said source alternately to the cathode of said one of said X-ray producers and to the anode of said other of said X-ray producers, a source of low tension current from which said high tension current is derived, means in the circuit of said low tension source controlling the energy delivered to one of said X-ray producers independently of the energy delivered to another of said X-ray producers, a fluorescent screen, and a shutter between which and said X-ray producers said screen intervenes operating in unison with said switching mechanism.

11. The combination with a plurality of X-ray producers, of a step up transformer, a connection from one terminal of the secondary of said transformer to an anode of one and a cathode of another of said X-ray producers, a synchronous switch connecting the other terminal of said transformer secondary alternately to the cathode of said one and the anode of said other of said X- ray producers, means in the primary circuit of said transformer controlling the energy delivered to one of said X-ray producers independently of the energy delivered to another of said X-ray producers, a fluorescent screen, and a synchronous shutter between which andsaid X-ray producers said screen intervenes; 7

12. The combination with a plurality of X-ray producers, of a transformer, one ter minalof whose secondary is connected with an anode of one and a cathode of another of said X-ra y producers,ca synchronous switch alternately connecting the other terminal of "said transformer secondary with the cathode of said one and the anode of said other of said X-ray producers, a synchronous switch in the prnnary circuit of said transformer delivering positive and negative currents to said primary circuit through different branches, current adjusting means in one of said branches, a shutter operatlng in unison with said switches, and a fluorescent screen intervening between said X-ray producers and said shutter.

13. The combination with, a source of alternating current, ofa transformer primary circuit having branches, synchronous commutating means delivering positive current waves through one of said branches and negative current waves through another of said branches, a plurality of X-ray producers, a connection from one terminal of the transformer secondary to an anode of one and a cathode of another of said X-ray producers, a synchronous switch connecting the other terminal of said transformer secondary alternately with the cathode of said one and the anode of said other of said X-ray producers, a shutter operating in unison with said switch, and a fluorescent screen intervening between said X-ray producers and said shutter.

In testimony whereof we have hereunto aflixed our signatures in the presence of the two subscribing witnesses.

HOMER CLYDE SNOOK. EDWIN W. KELLY. Witnesses:

ALICE S. MARSH, E. A. LYONS. 

